Cooling fan for radiator

ABSTRACT

A cooling fan is disclosed to have a hollow hub, and a plurality of blades respectively radially extending from and equiangularly spaced around the periphery the periphery of the hollow hub, the blades each having a distal end joined to one another to form a rim.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electric fans and more particularly, to a cooling fan for use in a motor vehicle to dissipate heat from the radiator of the motor vehicle.

2. Description of the Related Art

In a motor vehicle, a cooling fan is mounted on the radiator and driven by a motor to induce currents of air toward the radiator, thereby dissipating heat from the radiator into the outside open air.

When selecting a cooling fan, it is necessary to consider the performance of the cooling fan subject to the factors of air volume, noise level, wind pressure, type of bearing, and service life. The factor of air volume has a great concern with the diameter, thickness, revolving speed and blade design. Normally, a cooling fan of a relatively higher revolving speed provides a relatively heat dissipation effect. Fan blade thickness also determines the air volume. However, it is difficult to achieve a satisfactory heat dissipation effect while keeping the cooling fan in silence.

FIG. 1 shows a conventional cooling fan for this purpose. The cooling fan is fixedly fastened to the radiator and rotated by a motor to induce currents of air toward the radiator, carrying heat away from the radiator. The necessary working voltage for the motor is obtained from the car battery through the control of a control panel. According to this design, the cooling fan 12 comprises a plurality blades 14 equiangularly spaced around the hub. The blades 14 commonly have a smooth outer surface, and are spaced from one another at a gap. The gap between each two blades 14 wastes much workable air. Further, current vehicle radiators are made relatively finer than ever. Due to limited installation space, the size of the cooling fan for use with a radiator in a motor vehicle is limited. According to the aforesaid conventional design, the smooth surface blades 14 of the cooling fan 12 cannot induce sufficient air volume to dissipate heat from the radiator efficiently.

Therefore, it is desirable to provide a cooling fan for vehicle radiator that eliminates the aforesaid problem.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a cooling fan for vehicle radiator, which causes a high wind pressure during operation, thereby achieving a satisfactory heat dissipation effect. It is another object of the present invention to provide a cooling fan for vehicle radiator, which produces little noise during operation.

To achieve these and other objects of the present invention, the cooling fan comprises a hollow hub, and a plurality of blades respectively radially extending from and equiangularly spaced around the periphery of the hollow hub. The blades have the respective distal end joined to one another, thereby forming a rim. The rim that is formed of the distal ends of the blades enhances the wind pressure when the blades catching air during rotation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a cooling fan according to the prior art.

FIG. 2 is a schematic elevational view of a cooling fan according to the present invention.

FIG. 3 is a front view of the cooling fan according to the present invention.

FIG. 4 is a side view of the cooling fan according to the present invention.

FIG. 5 is a schematic drawing showing one installation example of the present invention.

FIG. 6 is a schematic drawing showing another installation example of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 2˜4, a cooling fan 22 in accordance with the present invention is shown comprising a hollow hub 24, and a plurality of blades 26 radially extending from and equiangularly arranged around the periphery of the hollow hub 24. The blades 26 each have the distal end respectively connected to one another, forming a rim that reinforces the structural strength of the cooling fan 22. Further, the connection between each two adjacent blades 26 is chamfered. The connecting portion between each adjacent blades 26 gives an extended fan blade area that increases the wind pressure when the cooling fan 22 is being rotated by a motor (not shown) to catch air, thereby enhancing heat exchange action of intake air with the radiator (not shown). The design of the invention also reduces noises. As it is well known that fan noise level has a great concern with the friction force between the blades and the air. Further, vibration of the cooling fan itself results in a high noise. The invention eliminates these problems. Because the distal ends of the blades 26 are joined together, the cooling fan 22 does not vibration when rotating, thereby reducing the noise level. Further, because the distal ends of the blades 26 are joined together, the distal ends of the blades 26 can catch air during rotation of the blades 26 with the hollow hub 24, thereby increasing the wind pressure and improving the performance.

According to fan affinity laws, the performance of a fan can be calculated by changing the test parameters during rotation of the fan. The change of the test parameters is applicable only to the same type of fans on the same performance curve. The relationship between wind pressure (P) and air density (γ) can be expressed as follows: P=γ

According to the aforesaid equation, wind pressure is indirectly proportional to air density Because the blades 26 of the cooling fan 22 according to the present invention can catch air of relatively higher density, the invention can obtain a relatively higher air pressure.

The cooling fan 22 can be installed in the top side of the radiator 32, as shown in FIG. 5. Alternatively, the cooling fan 22 can be installed in the bottom side of the radiator 32, as shown in FIG. 6. When started, the cooling fan 22 induces a big volume of air toward the radiator 32 to dissipate heat from the radiator 32 into the outside open air efficiently.

A prototype of cooling fan has been constructed with the features of FIGS. 2˜6. The cooling fan functions smoothly to provide all of the features discussed earlier.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. 

1. A cooling fan comprising a hollow hub, and a plurality of blades respectively radially extending from the periphery of said hollow hub and equiangularly spaced around the periphery of said hollow hub, wherein said blades each have a distal end joined to one another, forming a rim.
 2. The cooling fan as claimed in claim 1, wherein the connection area between the distal ends of each two adjacent blades is chamfered.
 3. The cooling fan as claimed in claim 1, which is installed in a top side of a radiator of a motor vehicle.
 4. The cooling fan as claimed in claim 1, which is installed in a bottom side of a radiator of a motor vehicle.
 5. The cooling fan as claimed in claim 1, which is coupled to a motor and rotatable by said motor.
 6. The cooling fan as claimed in claim 1, wherein hollow hub and said blades are molded from plastics.
 7. The cooling fan as claimed in claim 1, wherein said hollow hub and said blades are made in integrity. 